Causes and Risk Factors

Developmental disabilities begin anytime during the developmental period and usually last throughout a person’s lifetime. Most developmental disabilities begin before a baby is born, but some can happen after birth because of injury, infection, or other factors. Most developmental disabilities are thought to be caused by a complex mix of factors. These factors include genetics; parental health and behaviors (such as smoking and drinking) during pregnancy; complications during birth; infections the mother might have during pregnancy or the baby might have very early in life; and exposure of the mother or child to high levels of environmental toxins, such as lead. For some developmental disabilities, such as fetal alcohol syndrome, which is caused by drinking alcohol during pregnancy, we know the cause. But for most, we don’t. Following are some examples of what we know about specific developmental disabilities: At least 25% of hearing loss among babies is due to maternal infections during pregnancy, such as cytomegalovirus (CMV) infection; complications after birth; and head trauma. Some of the most common known causes of intellectual disability include fetal alcohol syndrome disorder; genetic and chromosomal conditions, such as Down syndrome and fragile X syndrome; and certain infections during pregnancy. Children who have a sibling with autism spectrum disorder are at a higher risk of also having autism spectrum disorder. Low birthweight, premature birth, multiple birth, and infections during pregnancy are associated with an increased risk for many developmental disabilities. Untreated newborn jaundice (high levels of bilirubin in the blood during the first few days after birth) can cause a type of brain damage known as kernicterus. Children with kernicterus are more likely to have cerebral palsy, hearing and vision problems, and problems with their teeth. Early detection and treatment of newborn jaundice can prevent kernicterus. The Study to Explore Early Development (SEED) is a multiyear study funded by CDC. It is currently the largest study in the United States to help identify factors that may put children at risk for autism spectrum disorders and other developmental disabilities. https://www.cdc.gov/ncbddd/developmentaldisabilities/facts.html